Residency rules get read as an architecture question: where does the data sit. That's the easy half, and it's usually the only half that makes it into the early design conversation.
The harder half shows up later, in how the thing is actually run.
Standard managed operations work from the outside in. The provider wraps its own tooling around your environment: monitoring, management, telemetry, all reporting back to the provider's platform. It is efficient precisely because it is centralised. One operations stack serving many customers.
For a regulated customer under strict residency requirements, that model quietly breaks. The operational exhaust the tooling depends on is itself data: the logs, the metrics, the telemetry. It cannot cross the sovereign boundary any more freely than the customer records can. The moment your monitoring calls home, you have moved regulated data out of the country you promised to keep it in.
So residency forces a different shape. The management and monitoring stack has to be deployed and run inside the customer's boundary, in their environment, not the provider's. Same operational outcome, fundamentally different delivery model, with real consequences for cost, for design, and for how you staff and run the service.
None of this is exotic once you have seen it. But it rarely surfaces in the early architecture discussion, because everyone is still thinking about where the data rests, not where the operation runs.
That's the point worth landing. Residency is usually framed as an architecture constraint. It is also an operating-model constraint, and that is the half people tend to discover mid-delivery, when the standard wrap won't fit and the plan has to change.
Ask it at the start: not only where the data lives, but where the work of running it actually happens.